The official winner of the Lawrence mayoral race will not be announced for at least another week, with dozens of possible votes still in question, city and state officials said Thursday.

Daniel Rivera, a city councilor, declared victory Tuesday, once the city’s unofficial count placed him 60 votes ahead of Mayor William Lantigua, who was running for a second term in the city of 77,000.

But city and state officials, who supervised the election, said that as many as 66 votes were still in question Thursday, including nine absentee ballots that have until Nov. 15 to arrive from overseas.

“There are enough votes out there to leave in question what the outcome will be,” said Charles Boddy, the city attorney.

Others cautioned that the outstanding votes are unlikely to change the outcome of the election because the ballots, if they are even counted, could go to either candidate.

On Friday afternoon, the city Board of Registrars will hold a public meeting to decide whether to count the bulk of the votes in question, about 54 provisional ballots filed by people who said they had registered to vote but were not on the voter list.

The four-member board currently has only three members: the city clerk, a Democrat, and a Republican.

The City Council voted 5 to 2 Wednesday against filling the vacancy on the board, said Councilor Marc Laplante. Rivera abstained from the vote.

Brian McNiff — spokesman for Secretary of State William F. Galvin, which supervised the city’s Nov. 5 elections — said 66 ballots are in question. He said the ballots include the 54 provisional ballots, three mailed-in ballots, and as many as nine overseas absentee ballots.

The roughly 15,000 ballots cast in the election are being stored in a sealed basement vault and guarded by a police officer around the clock.

The official winner of the mayoral race could be announced as early as Nov. 15, McNiff said. But Lantigua also has until that date to request a recount, which could prolong the process.

Rivera has urged Lantigua to concede and avoid a recount so that the divided city can prepare for a new mayor when the unemployment rate in Lawrence is the highest in the state, 15 percent.

But others said it is reasonable to request a recount in such a close race.

Lantigua, an immigrant from the Dominican Republic, made history in 2009 when he was elected the state’s first Latino mayor. Seventy-four percent of residents in Lawrence are Latino.

But his term has been marked by controversy, with three allies indicted on state corruption charges and a fourth convicted last month in federal court of bribery, lying to a federal agent, and obstruction of justice.

Both sides expressed confidence Thursday about prevailing in the race.

“If he didn’t think that there was a possibility of winning, he would have presumably conceded some time ago,” said Sal Tabit, Lantigua’s election lawyer. “It’s such a close race that I think his supporters and voters and the city and everyone else needs to make sure that all these votes that have been cast are counted and that they’re counted properly.”

David Torrisi, Rivera’s election lawyer and a former state representative from North Andover, said he did not believe the outstanding votes would make a difference.

“This is not Bush v. Gore,” he said, referring to the 2000 presidential election in which George W. Bush squeaked by Al Gore, with numerous Florida ballots in question.

City and state officials have said the Nov. 5 elections went smoothly. The state retrained all poll workers after complaints of disorganization in the September preliminary elections. On Election Day, Galvin said his office was in charge.

He said the state would only observe the Board of Registrars meeting Friday.